An ultra-thin oxide sub-1 V CMOS bandgap voltage reference

作者：Bohannon Eric^*; Washburn Clyde; Mukund P R

来源：International Journal of Circuit Theory and Applications, 2014, 42(8): 842-857.

DOI：10.1002/cta.1892

• analog
• direct tunneling
• gate current
• ultra-thin oxide
• bandgap voltage reference
• CMOS

This paper presents a sub-1 V CMOS bandgap voltage reference that accounts for the presence of direct tunneling-induced gate current. This current increases exponentially with decreasing oxide thickness and is especially prevalent in traditional (non-high-k/metal gate) ultra-thin oxide CMOS technologies (t(ox)%26lt; 3 nm), where it invalidates the simplifying design assumption of infinite gate resistance. The developed reference (average temperature coefficient, T-C_AVG, of 22.5 ppm/degrees C) overcomes direct tunneling by employing circuit techniques that minimize, balance, and cancel its effects. It is compared to a thick-oxide voltage reference (T-C_AVG = 14.0 ppm/degrees C) as a means of demonstrating that ultra-thin oxide MOSFETs can achieve performance similar to that of more expensive thick(er) oxide MOSFETs and that they can be used to design the analog component of a mixed-signal system. The reference was investigated in a 65 nm CMOS technology with a nominal V-DD of 1 V and a physical oxide thickness of 1.25 nm.

• 出版日期2014-8